'Programado por Kizar
Private Sub Form_Load()
    AllLocalDrives
    HookForm Me.hwnd
End Sub

Private Sub Form_Unload(Cancel As Integer)
    UnHookForm Me.hwnd
End Sub

'Programado por Kizar
Public Declare Function SetWindowLong Lib "user32" Alias "SetWindowLongA" (ByVal hwnd As Long, ByVal nIndex As Long, ByVal dwNewLong As Long) As Long
Public Declare Function CallWindowProc Lib "user32" Alias "CallWindowProcA" (ByVal lpPrevWndFunc As Long, ByVal hwnd As Long, ByVal Msg As Long, ByVal wParam As Long, ByVal lParam As Long) As Long
Public Declare Sub CopyMemory Lib "kernel32" Alias "RtlMoveMemory" (Destination As Any, Source As Any, ByVal Length As Long)

Public Declare Function GetLogicalDrives Lib "kernel32" () As Long
Public Declare Function GetDriveType Lib "kernel32" Alias "GetDriveTypeA" (ByVal nDrive As String) As Long

Public Type DEV_BROADCAST_HDR
    dbch_size As Long
    dbch_devicetype As Long
    dbch_reserved As Long
End Type

Public Const GWL_WNDPROC = -4
Public Const WM_DEVICECHANGE As Long = 537              'Cambios en un dispositivo
Public Const DBT_DEVICEARRIVAL As Long = 32768          'Cuando se conecta uno nuevo
Public Const DBT_DEVICEREMOVECOMPLETE As Long = 32772   'Cuando se desconecta uno
Public Const DBT_DEVTYP_VOLUME As Integer = 2           'Logical volume, cualquier unidad de almacenamiento nueva.

Dim PrevProc As Long
Dim lArray() As String

Public Sub HookForm(hwnd As Long)
    PrevProc = SetWindowLong(hwnd, GWL_WNDPROC, AddressOf WindowProc)
End Sub

Public Sub UnHookForm(hwnd As Long)
    SetWindowLong hwnd, GWL_WNDPROC, PrevProc
End Sub

Public Function WindowProc(ByVal hwnd As Long, ByVal uMsg As Long, ByVal wParam As Long, ByVal lParam As Long) As Long
    WindowProc = CallWindowProc(PrevProc, hwnd, uMsg, wParam, lParam)
    If uMsg = WM_DEVICECHANGE Then
        If wParam = DBT_DEVICEARRIVAL Then
            Dim dev As DEV_BROADCAST_HDR
            CopyMemory dev, ByVal lParam, 12
            If dev.dbch_devicetype = DBT_DEVTYP_VOLUME Then
                MsgBox USBConected
            End If
        ElseIf wParam = DBT_DEVICEREMOVECOMPLETE Then
            AllLocalDrives
        End If
    End If
End Function

Public Function USBConected() As String
    Dim hVolume As Long, i As Integer, b As Integer, find As Boolean
    hVolume = GetLogicalDrives()
    For i = 0 To 25
        If (hVolume And 2 ^ i) <> 0 Then
            For b = 0 To UBound(lArray)
                If lArray(b) = Chr(i + 65) Then find = True: Exit For
            Next b
            If find = False Then
                ReDim Preserve lArray(UBound(lArray) + 1)
                lArray(UBound(lArray)) = Chr(i + 65)
                USBConected = Chr(i + 65) & ":"
                Exit Function
            End If
        End If
        find = False
    Next i
End Function

Public Sub AllLocalDrives()
    Dim hVolume As Long, count As Integer, i As Integer
    Erase lArray
    count = 0
    hVolume = GetLogicalDrives()
    For i = 0 To 25
        If (hVolume And 2 ^ i) <> 0 Then
            ReDim Preserve lArray(count)
            lArray(count) = Chr(i + 65)
            count = count + 1
        End If
    Next i
End Sub